Background: Recurrent aphthous stomatitis (RAS) is one of the most common mucosal disorders of the mouth. The exact etiology of aphthous ulcer is uncertain, but precipitated factors include stress, trauma, food sensitivity etc. The aim of this study was to find prevalence of apthous ulceration and its association with psychological stress during exams among dental students of HITEC-IMS, Taxila. Methodology: A cross sectional study was conducted among 130 undergraduate dental students. The data were collected using questionnaires in two sections-1) Prevalence of occurrence of RAS was assessed by using a self reported questionnaire and 2) Stress factor was assessed by using perceived stress scale. Results: This study was carried out in 130 under graduate BDS students out of which 70% (91) experienced aphthous ulcer. 44 out of a total of 91 students with aphthous ulcer had moderate stress and 27 had severe stress. Perceived stress scores were considerably high in final year dental students (61.1%) (p=0.000). Among the student cohorts, final year BDS students were highly affected than others,which is statistically significant. Conclusion: This study confirms a significant association between psychological stress, especially during exams, and the occurrence of recurrent aphthous stomatitis (RAS) among dental students. Final-year students, who reported higher stress levels, exhibited a greater prevalence of RAS, indicating the impact of academic pressures. Addressing stress management in dental education could benefit students' overall health and reduce the incidence of RAS, promoting better well-being and academic performance among future dentists.